Note: Descriptions are shown in the official language in which they were submitted.
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FOOD CASING FOR MAKING INDICIA BEARING
FOOD PRODUCTS, METHOD FOR PRODUCING THE
CASING, METHOD FOR STUFFING THE CASING,
AND RESULTING FOOD PRODUCT
Technical Field
The present invention relates generally to
means for applying distinguishing marks or indicia
to the surface of food products such as sausage and
the like. More particularly, the present invention
relates to a food casing for manufacturing a
skinless sausage wherein the casing includes indicia
formed of an edible material and wherein the indicia
is transferable to the surface of the sausage
stuffed into the casing.
Backqround Of The Invention
It has been proposed to improve the eye
appeal of certain food products such as processed
meats by providing the food product with surface
ornamentation such as a logo, design or other
decorative pattern. For example, eye appeal of
skinless sausages, such as frankfurters and the
like, is improved by marking the surface to simulate
the burn mark pattern caused by grilling the
sausage. In one method, the application of the
so-called llgrill marks~ is accomplished by passing
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the frankfurters over hot wires to brand them.
However, this method has not been widely adopted by
the meat packing industry.
Casings most commonly used for
manufacturing encased food products such as
processed meat articles comprise relatively long,
thin-walled tubes of regenerated cellulose prepared
by extruding and then coagulating a viscose
solution. Cellulosic casings of regenerated
cellulose are either reinforced with a fibrous web
(hereinafter "fibrous casing") or unreinforced.
Unreinforced casing generally is used in preparing
smaller diameter products such as frankfurters and
the like whereas fibrous casings are used in
preparing larger diameter products such as bologna
and hams.
For convenience in handling, the casings,
which may be twenty to seventy meters or more in
length, are shirred and compressed to produce what
are commonly referred to in the art as ~shirred
casing sticks." These sticks, which measure about
twenty to seventy centimeters in length, may contain
upwards of 70 meters or more of casing. ~rocesses
for manufacturing cellulosic casings and for
subsequently shirring them to produce the shirred
sticks are well known in the art and will only be
described herein in sufficient detail to facilitate
an understanding of the present invention.
Utilizing the casing to apply markings to
the surface of a sausage has been attempted. For
example, in U. S. Patent No. 2,301,564 an aniline
ink is printed on the outside of the casing. During
sausage processing operations subsequent to stuffing
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the ink permeates and passes airectly through the
casing wall to the surface of the sausage meat. The
'564 Patent indicates that a clear outline of the
markings are reproduced on the sausage surface.
However, it is not believed that the clarity of the
marking on the sausage surface will satisfy
commercial requirements for sharpness and clarity.
For example, tests conducted with con~entional water
soluble food dyes such as U. S. Government approved
food, drug and cosmetic dye Red 40 (molecular weight
about 400) were successful in that a pattern of
grill marks printed on the outer surface of the
casing passed through the casing wall and indelibly
transferred to a frankfurter made by stuffing and
processing a frankfurter emulsion within the
casing. However, the diffusion of a low molecular
weight water soluble dye such as Red 40, through the
casing wall disperses the dye. The result is ~hat
the pattern transferred onto the food product is not
as sharp and distinct as the pattern initially
printed on the outer surface of the casing. Also,
the dye tends to diffuse into the body of the
frankfurter which further decreases the sharpness
and distinctiveness of the transferred pattern on
the surface of the frankfurter. Certain other known
coloring materials, such as liquid smoke and
synthetic brown dyes, have the same difficulty.
Accordingly, an object of an aspect of the
present invention is to provide a food casing having
indicia on one surface thereof which is substantially
nondiffusible into the casing and which is indelibly
transferable to a food product stuffed into the casing
in contact with the surface.
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An object of an aspect of the invention is to
provide such a casing in which the indicia is composed
of a material which remains on the casing surface to
which it is applied and subsequently transfers from that
surface directly onto the surface of a food product
stuffed into the casing and in contact with the casing
surface.
An object of an aspect of the invention is to
provide such a casing wherein the indicia forms a
pattern of grill marks which are transferable to the
food product.
An object of an aspect of the invention is to
provide a method for making such a food casing.
An object of an aspect of the invention is to
provide a skinless food product having surface
ornamentation derived from indicia located on a casing
surface in contact with the food product, and to a
method for making such a food product.
Various aspects of the invention are as follows:
A ready-to-stuff food casing article for making
indicia bearing food products comprising:
a) a shirred stick containing a length of
cellulosic casing having a moisture content of at least
about 20% based on the weight of dry cellulose, and said
cellulosic casing contained in said shirred stick being
adapted to turn inside out during stuffing for locating
an external cellulosic surface of said casing in direct
contact with a food product stuffed into said casing;
b) indicia disposed only on said external
cellulosic surface in an ordered repeated pattern
extending along the length of said casing and in mirror
image to the indicia desired on a said food product; and
c) said indicia composed of an edible coloring
material which is substantially nondiffusible into said
casing from said external cellulosic surface and
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indelibly transferable to a contacting surface of a said
food product stuffed and processed within said casing.
A food casing for use in preparing a processed food
product, said food product having its outer surface
marked with a desired, ordered indicia pattern that
extends along the length of the food product, said
casing comprising:
a) a length of extruded tubular cellulosic casing
having a cellulosic exterior surface and a cellulosic
interior surface;
b) indicia material disposed on said exterior
surface in an ordered pattern which extends along the
length of said casing in mirror image to said desired
ordered indicia pattern;
c) said indicia material being edible and
substantially nondiffusible from said exterior surface
and into said casing such that said interior surface
remains free of said indicia material;
d) said length of indicia-containing tubular
cellulosic casing being invertible so as to locate said
exterior surface and the indicia material thereon in
direct contact with a food product stuffed and processed
in said casing; and
e) said indicia material being releasable from
said cellulosic casing and indelibly transferable in
mirror image to the contiguous surface of a said food
product stuffed and processed in said length of tubular
cellulosic casing to form on a said contiguous surface
said desired ordered indicia pattern.
A food casing for making indicia-bearing food
products comprising a length of tubular cellulosic
casing having a first cellulosic surface adapted for
direct contact with a said food product stuffed and
processed in said casing, and a second, non-food
contacting surface opposite said first surface; indicia
material disposed only on said first cellulosic surface
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in an ordered pattern extending along said casing in
mirror image to the pattern desired on a said food
product, said indicia material being edible and
substantially nondiffusible from said first cellulosic
surface and into said casing such that said second non-
food-contacting surface remains free of said indicia
material; said indicia material comprising a mixture of
caramel and an additive to decrease the water solubility
of the caramel; and said indicia material being
releasable from said first cellulosic surface and
indelibly transferable to the contiguous surface of the
said food product stuffed and processed in said length
of cellulosic casing.
In the present invention, the casing used in the
manufacture of the encased food product is provided with
means for imparting a clear, sharp image of an
ornamentation, logo or other desired indicia to the
surface of the product processed within the casing.
In this respect, one surface of the cellulosic
casing is provided with indicia in mirror image to the
pattern desired on the surface of the food product.
During stuffing, the casing surface carrying the indicia
is brought into direct contact with the food product
stuffed into the casing. The indicia material comprises
an edible material which releases from the casing sur-
face and transfers to the surface of the food product so
that after stuffing and processing a mirror image of the
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pattern remains on the surface of the product when
the casing is removed.
To be effective, the indicia on the casing
surface should comprise a coloring material that
provides a distinct, sharp pattern. Casing
manufacturing and shirring operations performed
after application of the indicia material to the
casing should not smear or distort the indicia.
Otherwise, the pattern, when transferred to the
processed sausage, is blurred and/or distorted.
The indicia material may be applied in-line during
the production of the casing. If this is done, the
indicia material must remain on the casing during
subsequent handling of the casing including shirring
of the casing to produce the shirred stick and the
eventual deshirring of the casing to stuff it.
However, the indicia material should be releasable
from the surface of the casing on stuffing and/or
processing so the indicia can transfer to the
surface of the food product in contact with the
caslng.
The indicia material should lie on the
surface of the casing on which it was applied and
should not diffuse or otherwise substantially
penetrate into the casing wall. This will insure
that substantially all of the indicia material is
available for release and transfer to the food
product within the casing, thereby providing as
distinct a pattern as possible. It further is
necessary for the indicia material to remain on the
surface of the food as the casing is removed to make
a skinless food product.
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Application of the indicia material to the
casing can be accomplished by ar.y suitable means
such as by stenciling, spraying or printing. A
printing operation is preferred and will be
described further herein below. For purposes of
printing, the indicia material must be transferable
from the printing plate and onto the casing surface.
Summary Of The Invention
In one aspect, the present invention is
characterized by a food casing for making
indicia-bearing food products comprising a
cellulosic casing having a surface adapted for
direct contact with a food product stuffed and
processed in the casing: and an indicia material
disposed on said surface in a desired ordered
pattern extending,along said casing, said indicia
material being edible and substantially
nondiffusible from said surface and into said casing
and also being releasable from said surface and
indelibly transferable to the contiguous surface of
the food product stuffed and processed in the casing.
In another aspect, the invention is
characterized by a method of making an indicia-
transferring cellulosic food casing comprising
applying to the external surface of said food casing
an indicia in the form of a repeated ordered patte,rn
composed of an edible coloring material which is
substantially nondiffusible from said surface and
into said casing and which is indelibly transferable
from said surface to the contiguous surface of a
food product stuffed and processed in said casing.
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In yet another aspect, the invention is
characterized by a skinless proteinaceous food
product of the type which is processed as stuffed
material within a casing, said food product having
indicia arranged in an ordered pattern on the
surface thereof wherein said indicia is
substantially nondiffusible into the food product
from the surface thereof and is composed of an
edible coloring material which is substantially
nondiffusible into a said casing and is transferred
to said food product from a contacting surface of a
said casing during processing of said stuffed
material in a said casing.
In a further aspect, the invention is
characterized by a method of making an
indicia-bearing food product comprising:
a) providing a cellulosic casing
having a food product contacting surrace which
carries indicia composed of an edible coloring
material disposed on said surface in an ordered
pattern, said coloring material being substantially
nondiffusible from said surface into said casing;
b) stuffing a food product into
said casing so that the outer surface of the ~ood
product is in direct contact with sa.d casing food
product contacting surface;
c) processing said food product
within said casing to cook the product and indelibly
transfer said indicia from said casing surface to
the outer surface of the food product; and
thereafter
d) removing the casing to provide a
skinless food product having a mirror image of the
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indicia indelibly associated with the outer surface
of the skinless food product.
ln the invention, the indicia to be
transferred to the food product i6 applied to the
casing surface thereafter sometimes referred to as
the "food contacting surface") which comes in direct
contact with the food product processed within the
casing. Preferably the indicia is applied to the
outside of a tubular casing. Thereafter the casing
is turned inside out so the indicia is on an inside
or food contacting surface. The indicia forms an
ordered pattern which extends along the casing. To
simulate grill marks, the pattern takes the form of
parallel lines extending along the casing transverse
to the longitudinal axis of the casing. However,
the indicia could be in the form of any desired
ornamentation or pattern such as a company name or
logo and it could extend along one side or along
diametrically opposite sides of the casing.
Water is a constituent of most stuffable
food products. Also, many encased food products are
processed or cooked with steam or in a high humidity
environment such as a smoke house. Accordingly, it
is believed that the transfer of the indicia
material from the food contacting surface of the
casing and onto the surface of the food product
stuffed into the casing is facilitated if the
indicia material is water dispersible and preferably
if it is water soluble.
Indicia material of this type can be
incorporated into either a water or solvent based
system for purposes of applying it to the casing.
In either case, a mirror image of a desired pattern
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composed of the indicia material is applied to the
casing and dried. Thereafter, the moisture in the
stuffable food product or in the high humidity
processing environment will effect the release of
indicia material from the food contacting surface of
the casing so that the pattern can transfer directly
onto the surface of the food product in contact with
the casing and indicia material. Once the release
and transfer is effected, the indicia material
provides a substantially indelible mark on the
surface of the food product which remains even after
the casing is removed.
Indicia material suited for use in the
present invention is not significantly diffusible
into the casing wall so that substantially all the
indicia material is available for transfer to the
surface of the food product. ~xamples of
nondiffusible coloring materials considered suitable
include a natural or synthetic caramel, chocolate
and chocolate extracts, a carotenoid such as paprika
or saffron, carbon black and titanium dioxide. A
caramel based coloring material is the preferred
indicia material.
Caramel is a food approved coloring
material and is water soluble. It was found that
when the caramel is applied to the casing surface it
remains substantially on the surface and does not
migrate or diffuse to any significant extent into
the casing wall. This is attributed to the
molecular weight of the caramel which is composed of
constituents having molecular weights from below
2,000 to over 10,000. Accordingly, a large portion,
if not all, of the caramel which is applied to the
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surface of the casing is transferable to the food
product. Either a natural or a synthetic caramel or
other high molecular weight water soluble coloring
may be used provided it is edible.
Paprika, chocolate and chocolate extracts,
titanium dioxide and carbon black are examples of
nondiffusible coloring materials which have
molecular weights lower than caramel but
nevertheless are considered suitable for use. These
materials are generally not water soluble and for
this reason they would not readily diffuse through
the casing wall. However, they are water
dispersible and would be transferable from the
casing to the encased food product.
Application of the indicia material is
most easily accompliShed by passing the casing
through an applicator which prints or otherwise
applies a mirror image of the desired pattern onto
the outer surface of the casing. Since little, if
any, of the indicia material diffuses into the
casing, the casing must be inverted for stuffing so
that the outside surface of the casing having the
mirror image printed pattern becomes the casing
inside surface in direct contact with the food
product (i.e., th~ "food contacting surface'l).
Inverting the casing can be accomplished prior to
stuffing or during stuffing. U. S. Patent No.
4,162,557 discloses a method for inverting casing
prior to stuffing whereas U. S. Patent No. 4,162,693
discloses a method for inverting casing during
stuffing.
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Application of the indicia material onto
the exterior surface of the casing can be
accomplished "off-line~' after the casing
manufacturing process is complete or ~in-line~ as
part of the casing manufacturing process.
Briefly, a regenerated cellulose casing is
made by extruding a viscose solution through an
annular die into an acid regenerating bath. This
coagulates the viscose to form what is commonly
referred to as a "gel tube~. The moisture content
of this gel tube is over 200% based on the weight of
the cellulose. In a conventional process, the gel
tube is inflated and is passed through a dryer to
set the cellulose. The dried casing then is passed
in-line through a moisture equalizing chamber where
its moisture content is adjusted to facilitate
subsequent handling and processing. The in-line
dryer and moisture equalizing chamber are hereafter
collectively ref-erred to as the "dryerl'. On exit
from the dryer the casing has a moisture content of
about 13% to 18% based on the dry weight of
cellulose in the casing and is wound flat onto
reels.
To practice the present invention, an
in-line application of the indicia material can be
accomplished at the entrance to the dryer so that
the desired pattern is applied to the exterior of
the inflated gel tube. Preferably, the application
is by a printing means in the form of one or more
rolls which are driven by contact with the casing
passing into the dryer.
The drying temperature and retention time
of the casing in the dryer should be selected to
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permit the indicia material to dry sufficiently so
it does not block, stick or transfer to the opposing
layer of casing as the casing is reeled on leaving
the dryer. It has been discovered that when
caramel-based water soluble indicia material is
used, a temperature and retention time sufficient to
lower the moisture of the casing to a maximum of 14%
based on the weight of dry cellulose is sufficient
to eliminate such blocking, sticking or transfer.
If the casing within the dryer rubs
against guides or the like in the dryer before the
indicia material is sufficiently dry, the printed
patterns may smear along the casing. Accordingly,
passage of the printed inflated casing through the
dryer should be arranged to prevent, as much as
possible, a rubbing contact with the walls of the
dryer or with guides within the dryer. This can be
accomplished by supporting the casing within the
dryer on air bearings to avoid as much physical
contact as possible with the casing.
The casing can be shirred in a
conventional manner with the indicia material on
the exterior surface of the casing. lf this is
done, the casing is inverted during stuffing to
place the the indicia material on the inside of the
casing and in intimate contact with the food
products stuffed into the casing.
- As an alternative, the casing with the
indicia material on its exterior surface can be
inverted and then shirred. This places the indicia
material on an inside surface of the casing so there
is no need to invert the casing during stuffing.
1 335 1 64
It is conventional during the course of
shirring a cellulosic-casing to spray the interior
surface of the casing with an aqueous solution. For
example, U. S. Patent No. 3,981,046 describes a
conventional humidification technique in which an
aqueous solution is applied as an internal spray to
humidify the casing to raise the moisture content of
the casing to a level better suited for shirring and
subsequent stuffing. In the event the casing is
shirred with the indicia material on the outer
surface of the casing, this conventional
humidification technique can be used. However, if
the casing is inverted prior to shirring, this
conventional humidification technique should be
altered as discussed below so as to prevent the
aqueous solution from degrading the water soluble
indicia material.
Drawinqs
Figure 1 is a schematic representation of
part of a cellulosic manufacturing system suitable
for making the casing of the present invention;
Figure Z is a view on an enlarged scale
showing an end view of a component preferably used
in the manufacturing system:
Figure 3 is a perspective view showing an
applicator suitable for applying the indicia
material to the casing according to the Figure 1
system;
Figures 4 and 5 are schematic
representations of alternate systems for shirring
the indicia-containing casing of the present
invention;
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Figure 6 is a perspective view showing a
section of one casing embodiment of the present
invention wherein the indicia applied to the outside
surface of the casing simulates grill marks;
Figure 7 is a perspective view showing a
portion of a skinless food product having surface
ornamentation in the form of simulated grill marks
as made using the casing of Figure 6;
Figure 8 is a view showing a flattened
casing having indicia applied thereto representing a
corporate logo; and
Figure 9 is a view showing a skinless
frankfurter made using the Figure 8 casing.
Detailed Description Of The Invention
Referring to the drawings, Figure 1
illustrates a portion of a process for manufacturing
the indicia containing cellulosic casing of the
present invention. In this process, a viscose tube
12 is extruded and passed through one or more
solution t,anks 14 to coagulate and treat the
viscose, thereby forming a cellulosic casing 16. At
t,his stage the casing is in a gel state and has a
moisture content of over 200% based on the dry
weight of the cellulose in the casing. The casin~
then passes longituainally through a dryer 18. Nip
rolls 20,22 at the dryer inlet and outlet maintain
the casing in the dryer in an inflated condition to
prevent diametrical shrinkage and to facilitate
drying. On leaving the dryer the casing is wound
flat onto a reel 24.
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According to one embodiment of the present
invention, an applicator means generally indicated
at 26, is arranged at the dryer inlet. This
applicator 26 is arranged to apply a transferable
indicia material in mirror image to a desired
pattern to the exterior surface of the gel state
casing. As further discussed herein, a preferred
indicia material is a dispersion or an aqueous
solution of a caramel based coloring. Accordingly,
for purposes of illustration, the indicia material
is sometimes referred to hereafter as being caramel
or caramel based.
As shown in Figure 1, applicator 26
includes a reservoir 28, an absorbent foam roller 30
and a printing wheel 32. The reservoir 28 contains
a supply of the indicia material which is delivered
to foam roller 30. Foam roller 30 is in direct
contact with printing wheel 32 so that the indicia
material on roller 30 is transferred to the printing
wheel. The printing wheel 32 has a printing surface
34 engraved with the mirror image of the pattern
desired on the food product. In the embodiment as
shown, the desired pattern is intended to simulate
grill marks to enhance the eye appeal of a skinless
frankfurter or the like. For this purpose, the
printing wheel surface 34 has a plurality of raised
cogs or teeth 36 (Figure ~) for applying an ordered
pattern of equally spaced simulated grill marks 38
directly to the exterior surface of the casing in
the gel state. Diametrically opposite the printing
wheel 32 is an opposing support wheel 40. It should
be appreciated that this opposing support wheel 40
also can be a printing wheel.
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l 335 l 64
To function properly, printing wheel 32
must receive and retain a supply of the indicia
material from the foam roll 30 and in turn transfer
it onto the cellulosic casing outer surface. When
applying an aqueous solution of a caramel-based
coloring to the casing as the indicia, a suitable
printing wheel is a roller made of compressed Nylon
fibers.
Smearing of the pattern on application to
t.he exterior surface of the gel state casing is
avoided by matching the peripheral speed of the
printing wheel 32 to the linear speed of the casing
16. This can be accomplished by using the casing to
drive the printing wheel through friction, or by
driving the printing wheel with other means (not
shown) to provide the proper matching of speeds.
The indicia material is readily applied to
the high moisture casing 16 entering the dryer 18.
The dryer temperature and retention time should be
sufficient to lower the casing moisture content to a
level where the indicia material is sufficiently dry
to prevent sticking or offsetting onto an opposing
layer of the casing in reel ?4. When caramel is
used, the moisture content of the casing leaving the
dryer should be not more than about 14% based on the
weight of dry cellulose. At casing moisture above
about 14%, the caramel still has sufficient tack to
block, stick or offset onto an opposing layer of the
casing as the casing is wound onto reel 24. Drying
of the indicia material can be accelerated by
suspending it in a solvent solution rather than in
an aqueous solution.
Within dryer 18, it is conventional to
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1 3351 64
provide guides (not shown) at spaced intervals to
support and guide the relatively long spans of
casing passing through the dryer. It was found that
guides which support the casing by direct contact
caused smearing of the just-applied indicia
material. One method to prevent this smearing is to
maintain an orientation of the casing in the dryer
which positions the indicia-marked portion of the
casing outer surface away from contact with the
guides. A preferred solution is to provide guides
in the form of air bearings which avoid physical
contact with the casing.
One form of such an air bearing guide for
use in the dryer is a substantially y-shaped guide
generally indicated at 42 in Figure 2. The arms 44
of the y-shaped guide contain a plurality of air
passages (not shown) which direct streams of air 46
against the casing 16 to support the casing and
prevent direct physical contact between the casing
and guide. The air flow required to support the
casing varies depending upon the casing size and the
distance between guides. Determination of the
proper air flow ifi well within the skill of the art.
Figure 6 illustrates one casing embodiment
of the present invention wherein the indicia 52 is
formed of a caramel-based coloring. Afi sh~wn, the
indicia S2 is in the form of a repeated ordered
pattern applied to and extending along the casing
exterior surface 56. The repeat and order derives
from applying the caramel coloring onto casing
exterior surface 56 as the casing 16 moves at a
relatively constant speed across a printing wheel 32
rotating at the same speed (Figure 1). The
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particular pattern illustrated in Figure 6 is
composed of a plurality of short parallel line
segments 38 disposed transverse the longitudinal
axis 15 of the casing to simulate grill marks.
The grill marks 38 are disposed on a
surface of the casing adapted to come into direct
contact with the food product stuffed into the
casing. Since the indicia 52 is d-isposed on an
exterior surface 56 of the casing and is
substantially nondiffusible into and through the
casing wall, the casing must be inverted either
before or during stuffing to locate the pattern 52
on the inside of the casing.
Figures 4 and 5 illustrate alternative
methods for shirring the indicia-containing casing
16 illustrated in Figure 6. In Figure 4, reel 24
from Figure 1 contains casing 16 having indicia
composed of pat~ern of grill marks 38 on its outer
surface. Casing from this reel is unreeled and fed
directly to a conventional shirring machine
generally indicated at 60. Shirring proceeds in a
conventional manner in that the casing 16 is
inflated and fed onto a mandrel 54. The casing
passes along the mandrel and through a conventional
shirring head 58 which gathers the casing into
pleats and forms a shirred stick indicated at 62.
The shirring mandrel 54 is hollow so that an aqueous
shirring solution can be delivered as a spray 64 to
the interior of the casing. As mentioned
hereinabove, a conventional shirring solution
includes a water phase. This is applied in an
amount sufficient to~rehumidify the casing in order
to raise the moisture content from about the 14%
19 - 1 335 1 64
level of the reeled casing to a level suitable for
shirring and stuffing. In the shirring method as
shown in Figure 4 the total moisture added by the
shirring solution would be about 12% to 14% in order
to raise the casing moisture content from about the
14% level of the reeled casing to about 26% to 28%.
The shirred stick 62 formed in this
fashion contains casing having the indicia e.g.,
pattern of grill marks 38, on an outside surface.
Accordingly, this stick would be inverted during
stuffing so as to locate the pattern of grill marks
38 on the inner surface (i.e., the food contacting
surface) of the casing. Inversion during stuffing
is accomplished by turning and passing the casing
through the bore of the stick as generally shown,
for example, in U. S. Patents Nos. 4,292,711 and
4,162,693.
In Figure 5, the casing from reel 24
(Figure 1) is first unreeled and broken down into
shorter lengths. These shorter lengths are then
inverted and rewound onto a new reel 24' as
generally shown in U. S. Patent No. 4,16Z,557. This
locates the indicia composed of the pattern of grill
marks 38' on an inside surface of the casing. The
casing is then unreeled from reel 24' and fed
directly to a conventiona1 shirring machine 60'. As
an alternative, the '557 ~atent says the inverted
casing can be fed directly to a shirring machine.
If the indicia comprising the pattern of
grill marks 38' is formed of a water soluble
material such as a caramel coloring, it has been
discovered that the internal spraying of an aqueous
shirring solution for rehumidifying the casing
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should be modified from conventional practice. In
particular, the water content of spray 64' is
reduced so as not to wash off the indicia material
or otherwise destroy the integrity of the pattern.
This may be accomplished by adding about 3% to 4%
moisture in the internal spray of shirrinq solution
to raise the moisture content of the casing from
about the 14% of the reeled casing to about 17% to
18%. This provides the casing with sufficient
moisture for shirrin~. After shirring, an
additional 6% to 8% moisture can be externally added
by a water applicator 64 which sprays moisture onto
the outside surface of the stick 62' immediately
after shirring. This amount of external spray is
sufficient to raise the moisture level of the casing
to about the 26% to 28% preferred for stuffing.
Since the indicia composed of the pattern
of grill marks 38' is on an inside surface of the
inverted casing, the stick produced by shirring the
inverted casing can be stuffed in a conventional
fashion and is not inverted during stuffing.
The method of applying indicia in-line
with the casing manufacturing process as disclosed
in Figure 1 is suited for relatively simple indicia
patterns such as the grill mark pattern
illustrated. However, a slightly different
application method is preferred for applying a
corporate logo or other indicia involving a design
more intricate than the straight lines required to
simulate grill marks.
Preferably, application of a more
intricate design to the casing is made in an
off-line operation so the indicia can be applied
- 21 -
1 335 1 64
while the casing is in a flattened condition.
Application to flattened casing will improve the
likelihood that a clear sharp image of the more
intricate design is applied to the casing.
To apply the indicia material off-line,
the high moisture gel casing is dried to about 13%
to 18% moisture, flattened and then is wound onto a
reel. The reel is then transported to an indicia
applying operation where the casing is unwound. As
the casing is unwound from the reel, the indicia is
applied to the flattened casing. If desir~d, a
conventional peeling aid such as carboxymethyl
cellulose (CMC) can be applied to the exterior
surface of the gel state casing entering the dryer.
Thereafter, the indicia material is applied directly
onto the CMC coated surface.
Figure 8 shows a section of flattened
casing i~' wherein the indicia 76 applied to the
outer surface of the casing is a mirror image of a
corporate logo. The logo extends along the casing
in a repeated ordered pattern as the result of
applying the indicia material to the casing in a
continuous operation as the casing unwinds from its
reel. After the indicia material is applied, the
casing goes through a second drying operation to set
t.he indicia material, and then is rewound. The
additional drying step lowers the casing moisture
content to well below 14%. At this ]ow moisture
level the casing is too brittle for shirring so it
should be rehumidified to about the 14% level prior
to commencing the shirring operation.
To demonstrate the invention, an in-line
application of grill marks to a frankfurter size
_ 22 - 1 3351 64
cellulose casing was accomplished using the system
shown in Figure 1. In this respect, a printing
wheel made of compressed Nylon fibers applied a
caramel coloring material in a grill mark pattern to
the high moisture gel casing entering the dryer.
The caramel used was a double strength acid proof
caramel color having a solid content of about 51%
which is sold by Sethness Products Company as
No. DS 400. This caramel color comprises
constituents of various molecular weights. In
particular, 27 wt.% of the caramel constituents have
molecular weights above 10,000: 14 wt.% are in the
2,000-10,000 range; and 59 wt.% are below 2,000.
The casing was dried to a moisture content of about
14% based on the weight of dry cellulose and reeled
on exit from the dryer. The casing then was shirred
with the grill mark pattern on the outside surface
as shown in Figure 4 while applying an internal
shirring solution to raise the casing moisture level
to about 26% to 28%.
During the shirring of cellulosic casing
for frankfurters, it is conventional to twist the
shirred stick to improve the straightness of the
stick. U. S. Patent No. 3,398,069 and No. 4,649,961
disclose methods for radially displacing the pleats
of shirred casing one from another by imparting a
twist to the stick during shirring. While a method
and stick as disclosed in U. S. Patent No. 4,649,961
is preferred, for purposes of this test the casing
was shirred without twisting and instead the shirred
sticks were supported on dowels to preserve
straightness.
- - 1 3 3 5 7 6 4
' The shirred casing then was stuffed with a
commercially available frankfurter meat emulsion
using a commercial frankfurter stuffing machine
known in the art as a Townsend FRANK A MATIC or
"FAM" machine. During stuffing the casing is
deshirred and inverted through the bore of the stick
so the casing turns inside out. This locates t,he
grill marks on the inside surface of the casing.
Conventional operation of t,he FAM requires
that the shirred casing spin about the stuffing horn
(see U. S. Patent No. 3,115,668). Consequently, the
inverted deshirred casing as it turns into the bore
of the shirred stick and passes along the stuffing
horn, may twist and seize onto the horn causing the
casing to break. To reduce the likelihood of t,he
casing seizing onto the horn and to facilitate t,he
inversion during stuffing, the FAM stuffing horn was
coated with a low friction material i.e., Teflon.
Also, the shirred casing stick was maintained
centered about the stuffing horn during stuffing to
insure an annuiar clearance space between the horn
outside diameter and the stick inside diameter for
the passage of the casing being deshirred through
the stick bore. Maintaining the centering of the
shirred stick is accomplished by modifying the
follower of the FAM so it fits over and supports the
end of the stick.
It is possible to still further reduce t,he
likelihood of the inverted casing seizing on the
stuffing horn by using a stick as disclosed in U. S.
Patent No. 4,649,961. In this respect, the FAM
generally spins the shirred casing about the
stuffing horn in a clockwise direction during
1 335 1 64
spinning (looking in a direction into the stuffing
horn). A stick as disclosed in U. S. Patent No.
4,649,961 which has its pleat twist oriented in a
direction opposite to the FAM spinning direction
will counter and offset the tendency of the spinning
inverted casing to twist and seize onto the horn.
After stuffing, the stuffed casing was
processed at about 20% relative humidity to cook the
emulsion and the casing was removed to produce
skinless frankfurters bearing the desired grill mark
indicia. lt was found that substantially all the
caramel coloring material transferred from the
casing to the surface of the frankfurter so that
only a slight stain of caramel residue remained on
the casing. Moreover, the grill marks on the
skinless frankfurters were found to be indelible in
that they could not be removed by manual rubbing and
remained intact even after a further cooking of the
skinless frankfurter in boiling water. Thus, even
after boiling, the skinless frankfurters have the
eye appeal of grilled frankfurters.
As a further demonstration, casing from
reel 24 was inverted and then shirred according to
the arrangement illustrated in Figure 5. The
internally sprayed shirring solution, including
carboxymethyl ce]lulose (CMC) as a peeling aid, was
applied at a rate calculated to raise the moisture
content of the casing about 4% (i.e., to about 18%
based on the weight of dry cellulose) and to apply
CMC to the interior of the casing at the rate of
about 3.2 mg/100 in . After shirring, an
additional 8% moisture was added to the external
surface of the casing. The shirred casing was
z5 ~ 3351 ~
stuffed with a frankfurter emulsion using the FAM
machine in a conventional manner, after which the
stuffed casing was processed to cook the emulsion,
and the casing was removed to produce skinless
frankfurters. It was found that while the grill
marks did transfer to the frankfurter, the marks
were not as clearly defined as in the previous
tests. It is speculated this is due in part to the
application of the aqueous shirring solution
directly onto the casing surface containing the
water soluble grill marks. However, the transferred
grill marks are indelible in that they cannot be
rubbed off and survive boiling of the frankfurter.
Another caramel found suitable for use is
Sethness Products Company No. 858. This is similar
to DS 400 except it is sold in powdered form and can
be used in a 50 wt.% aqueous solution (i.e., 50% by
weight caramel powder and 50% by weight water).
It has been found that a shirred
ready-to-stuff casing having the caramel coloring
indicia material preferably should be stuffed within
a week of shirring. If stored for longer periods in
a ready-to-stuff condition, the caramel coloring
material is solubilized by t-he moisture in the
casing and starts to bleed along the casing surface
and offset to an adjacent pleat. The result on
stuffing is a blurred, distorted and less defined
image appearing on the skinless food product.
The storage period can be increased by
lowering the moisture content of the casing although
stuffing at less than optimum moisture levels risks
an increase in the breakage rate of the casing. It
also has been found that the storage period can be
- 26 - 1 3351 64
increased by mixing the caramel coloring with
additives to render the caramel less soluble. For
example, mixing the caramel with Kymene~ has been
found to allow storage of a ready-to-stuff casing
for two weeks and more without encountering the
aforesaid bleeding and offsetting of the caramel
coloring material. Kymene is a cationic resin sold
by Hercules Chemical Company. A suitable mixture
for rendering the caramel coloring less soluble
comprises 35 wt.~ water, 35 wt.% No. 858 caramel
powder and 30 wt.% Kymene.
Another type of casing customarily used in
food processing comprises short cut lengths of
~ibrous casing ranging up to six feet in length.
These casings are sold in a relatively dry state and
are soaked in water just prior to stuffing to
provide the required moisture content. Accordingly,
the aforesaid storage period limitations would not
exist if the caramel coloring is applied to this
type of casing. However, provision must be made to
prevent the caramel coloring from being washed off
the casing during soaking.
Figure 7 illustrates a skinless
frankfurter 70 made in the Figure 6 casing. The
frankfurter has a pattern on its outer surface
derived from indicia material applied to the casing
in which the frankfurter was made. In the
embodiment shown, the pattern simulates grill marks
38~1 in mirror image to the pattern 52 on the casing
(Figure 6). It should be noted that the grill marks
are composed of the caramel coloring material
indelibly transferred to the frankfurter surface.
As shown in Figure 7, the grill marks 38" are
~ n-
- 27 - 1 3351 64
restricted substantially to the frankfurter surface
72 and the coloring material does not to any
significant extent diffuse into the body 74 of the
frankfurter beneath the surface.
Figure 9 illustrates a skinless
frankfurter 80 made using the casing embodiment of
Figure 8. Here the frankfurter carries a more
intricate indicia comprising a corporate logo 76'
which is in mirror image to the logo 76 on the
casing 16'.
While the invention has been described
with respect to the production of skinless
frankfurters in shirred cellulosic casing, it should
be appreciated that the present invention also can
be applied to the processing of any encased
proteinaceous food product. For example, t.he
invention can be used to provide other food articles
which are processed in cellulosic food casings or
wraps with a desired surface ornamentation.
Particular examples in addition to skinless
frankfurters, include, but are not limited to,
cheese, bologna, chopped and formed hams, process
hams and poultry products.
In the foregoing examples, a dark higher
molecular weight caramel was used to simulate the
dark brown color of grill marks. A lower molecu7ar
weight caramel would be used to provide a lighter
brown color for the indicia. Other suitable
coloring materials can be selected to provide colors
for other types of indicia such as corporate logos
or designs.
It is not essential that the food product
be processed, and the casing removed, prior to the
- Z8 ~ 1 335 1 64
food product reaching the consumer at the retail
level. For example, the encased food product can be
sold at the retail level wherein the consumer cooks
the food product and removes the casing.
Thus, it should be appreciated that the
present invention accomplishes its intended objects
in providing a casing for making a indicia-bearing
skinless food product wherein the casing includes
the indicia which is indelibly transferable to the
food product processed within the casing.
